GetCallerAccessRights method of the __SystemSecurity class

The
__SystemSecurity::GetCallerAccessRights method sets the rights parameter as a bitmap with each bit corresponding to an access right. Any client can call this to determine which rights the client has. This method is useful for clients that enable or disable features. For example, a GUI application might disable a button if the currently logged-on user does not have method execution rights.

Any enabled client has the right to call
GetCallerAccessRights, even if that client does not have general method execution rights.